8 ounces pancetta, chopped
4 large garlic cloves, chopped
4 large egg yolks
2 large eggs
1 ½ cups grated Parmigiana Reggiano (plus more to sprinkle when serving)
1 pound dry spaghetti
¼ cup salt
1 ½ teaspoon fresh cracked black pepper
¼ cup chopped flat leaf parsley (plus more for garnish)
Place the pancetta in a large frying pan over medium heat. Sauté until crisp, stirring frequently, about 4-5 minutes. Add the garlic and turn the heat to medium low and cook for another minute until garlic is soft and fragrant. Turn off the heat.
Whisk the egg yolks and whole eggs in the bottom of a large bowl until well beaten. Add 1 cup of the cheese and whisk to combine. Set aside. It is important that you do this step before cooking your pasta so that your pasta is very hot when you mix in the eggs, so they cook from the heat of the pasta and create a velvety sauce.
Bring a large pot of water to a boil. Add the salt when bubbles start to form. Cook the spaghetti for 8-10 minutes until al dente (slightly firm) in texture. Reserve ½ cup of the pasta water before draining.
Drain the pasta and add it immediately to the pancetta and garlic. Return the heat to medium low and toss to combine.
Slowly whisk ¼ cup of the hot reserved pasta water into the eggs to temper them so they do not scramble when you add the pasta. Immediately add the pasta into the bowl with the eggs and immediately and vigorously begin tossing to incorporate the eggs and cheese in the pasta. Toss continuously for 1 full minute. Add the remaining ½ cup cheese, black pepper, and the remaining pasta water to the bowl and toss for at least another full minute until a creamy sauce has formed. Toss in the parsley.
Serve with additional cheese on the side, garnished with parsley.